1. Field of the Invention
The present invention relates to endless transmission belts and more particularly to a belt tensioner and tensioner position indicating device for developing an indication of the condition of the endless transmission belt.
2. Description of the Problem
Front end accessory components for a truck engine, such as an air conditioning compressor, a power steering pump, an alternator and a cooling fan, and internal engine components such as cam shafts and oil pumps, are often driven by one or more endless transmission belts installed between a rotatable element of the vehicle's engine, typically the engine crankshaft, and a pulley for the driven component. It is undesirable for these belts to slip since slip produces, belt wear, frictional losses and loss of output from the driven component. In addition, slip can indicate the possible deterioration of the belt and its possible separation or detraining from its pulleys. Maintaining belt tension reduces slip and extends the life of endless transmission belts by taking slack out of the endless loop. However, simply maintaining tension on a belt becomes less effective with aging of the belt due the belt's loss of elasticity.
Good belt operation is considered important enough that checking belt tension has been made part of the commercial vehicle standard pre-trip inspection. Drivers have had to feel the belts to determine belt tightness, unless a belt is so loose that a gap is visually detectable. However, belt slippage due to deterioration in the condition of the belt can occur before a loose belt becomes detectable by touch or sight. Direct inspection can also be cumbersome, involving the movement of heavy or large hoods to reach the locations of the various belts. For a driver who suffers from impaired mobility, these tasks can be very difficult and time consuming.